Oh dear, where's D. W. Cockburn when you need him? He'd know what to do!
Water pipe bonding
- Thread starter davecooper
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- bonding water pipe
No.
It can.
But for it to be an e-c-p it has to have the property of being liable to introduce a potential.
Has anybody ever seen him and Bernard together at the same time?
So, then it IS an e-c-p.
What has happened to the 'quoting'?
When clicking 'quote' on your post, my question which you quoted does not appear.
No, only if it is liable to introduce a potential.
Dunno - I'm seeing the same problem.
My guess is a software upgrade. This new forum package does have some nice features compared to the previous one, but it is a bit flaky. Not so much actual bugs, but often exhibits the results of stupidity by the designers.
But the reasoning for not earthing the pipework in that case could also be used as an argument not to earth the metal casing of a class I appliance.
But who goes around deciding or changing bonding arrangements on such unknown things?
But they are not metallically contiguous items running all around the house.
It was considered valid enough for decades when the wiring regs. specifically required the earthing of the whole metallic pipework system, metal tubs and sinks etc.
No. They are exposed-conductive-parts of electrical appliances and may become live because they contain live parts.
Those designing electrical installations - and not bonding - earthing.
No, but just as unlikely to become live and likely to be touched by someone grateful they do not provide a path of negligible impedance to earth.
I don't know why they decided that then but they were wrong.
Spoons again.
Goodness me, I wish I had come across this thread sooner, a couple of weeks ago I received an electric shock from my kitchen sink! My frayed kettle lead was wrapped around the kitchen tap and one of the wires had got trapped between the bottom of the tap and the sink, the sink then became live!! I know now to wrap up the exposed parts of the kettle lead with tape. To be extra safe I asked a neighbour about it and he said the sink probably needed earth bonding so I bought this book from Amazon which helped explain what I needed to do. I now have quite a lot of earth wires around the kitchen but at least the sink won't become live again.
The book also prompted me to check the leads near the radiators, almost all the radiator pipes had frayed flexes around them! What an eye opener! I have ordered some more earth wire to make the radiators safe, and as also noted in the book, I will put earth wires to the wrought iron newel posts on the stairs to protect against shock when the vacuum cleaner flex rubs against them.
The book also prompted me to check the leads near the radiators, almost all the radiator pipes had frayed flexes around them! What an eye opener! I have ordered some more earth wire to make the radiators safe, and as also noted in the book, I will put earth wires to the wrought iron newel posts on the stairs to protect against shock when the vacuum cleaner flex rubs against them.
Sure, but the point I was trying to make is that if you're saying that pipework should not be earthed because of the possibility of somebody sustaining a shock by contacting some other live point while also in contact with that pipework, exactly the same argument could be made for not earthing anything else. Doesn't the earth on that metal-cased class I wall heater pose a similar possibility of shock to some live conductor as an earthed kitchen sink?
Comparing with spoons, door hinges, and similarly trivial items is silly, because they're not expansive collections of metalwork which spread around multiple rooms of the house.
The old wiring regs. contained a similar "segregate or bond" requirement for things, but also recognized the fact that effective segregation of an extensive metallic pipework system is not practical, and thus specified that it must be earthed.
If you are that concerned about the earth potential on the radiator pipes, kitchen sink, bath tabs, etc., posing a risk, what steps do you take to ensure that they can't be earthed by some incidental/accidental path? Do you insist on plastic couplings everywhere so that, for example, an earthed metal appliance placed on a stainless steel kitchen sink won't introduce earth potential throughout the plumbing? Do you insist on something which ensures that a washer or cooker pushed up again the rim of the sink won't do the same? Do you insist on insulating couplings at the hot-water cylinder, so that pipework won't be earthed via the immersion heater connection?
..but it is the most likely hazard against which we protect.
It is a compromise; we can't do both.
Yes, but less likely a danger than not earthing it.
Not really silly.
If earthed unnecessarily it would be a hazard in both directions - best not to do it.
Ok. They have changed their mind.
You cannot. It is a compromise.
I have previously stated that that would be a good thing to do.
Lengths of plastic pipe at entry and strategic positions rather than just couplings.
It is a compromise - you may if you wish.
Your socket on the left is wonky
Doesn't your understanding extend to understanding the difference between exposed-conductive-parts, extraneous-conductive-parts, and things which just happen to be conductive because they are made out of conductive materials such as metal?
So when the regulations change, and introduce a requirement for increased safety which you think is not necessary, you say "Pah - what a load of gonads, if it was OK in the past it must be OK now".
And when they change and remove a requirement which you think is necessary you say "Pah - what a load of gonads, if it was needed in the past it must be needed now".
Do you recall what I have said before about your pathological refusal to accept the idea that things change?
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Believe me that's the least of the problems with this awful kitchen...Your socket on the left is wonky
Totally agree, if you can see that the spoon in not in contact with any wires then you know it is not going to be Live and hence is safe to touch.
When a metal pipe goes through a wall or under the floor it is not possible to see if it is ( or has ) come into contact with a wire.
Two taps, one conected by a fault to Live and the other one floating ( potential wise ) at the end of a length of copper pipe ( no bond or earth connected to the pipe ).
Is it safe to hold both taps at the same time ? That depends on how much current will flow through the body of the person holding the two taps. One could say that no current can flow because the second tap is not earthed. It has a path to earth via capacitive coupling to earthed objects, it has a path to earth via the water in the pipes.
10 milliamps across the chest can be fatal, 10 milliamps is possible through capacitive coupling.
When the tap becomes Live no protective device will operate. When the person completes the circuit they will get a shock which may or not be fatal ( or serious permanent muscle damage ) Still no protective device will operate.
If the taps are bonded together then there is no risk of current flowing across the chest.
If the second tap is earthed ( via earthed or bonds in other rooms ) when the first tap becomes Live then the current across the chest will be a lot higher, high risk of fatal shock.
So you could advocate that isolation sections are fitted to all taps and hope the iwater in the isolation section does not bridge the isolation sufficiently to allow fatal levels of current to flow in or out of the tap.
Or you can simple ensure the two taps are never at different potentials by bonding them together.